This invention relates to a sleeve lubricating method and a sleeve lubricating mechanism, in which a powder lubricant is coated on an inside surface of a molten metal feeding sleeve for a vertical shot casting machine.
Water dispersion of graphite or inorganic substance (such as talc, mica etc.) has conventionally been used for a lubricant. This water dispersion has been sprayed onto the inside surface of the molten metal feeding sleeve for the vertical shot casting machine, while vertically moving an atomizer and an air blow nozzle attached to a drive device. In other words, the water dispersion has been sprayed from the atomizer, and moisture of the sprayed water dispersion has been removed by the air blow nozzle.
However, the above method spraying the lubricant forming the water dispersion has included the following problems.
(a) The lubricant has been scattered to stain places around the sleeve. Especially, the graphite water dispersion has caused a worse working environment.
(b) High air blow noise emitted when removing moisture and requiring an operator to have a soundproof device on, have caused a worse workability.
(c) Clogged atomizer and air blow nozzle unable to coat the lubricant uniformly, have probably induced to ununiformity of product quality.
In order to eliminate the troubles induced by using the water dispersion for the lubricant, use of a powder lubricant has been tried. However, it has been difficult to positively coat the powder lubricant onto the inside surface of the sleeve.